I am planning on buying the ASRock AB350 PRO4, but when reading through the specs on the website, I found that the os is Microsoft® Windows® 10 64-bit, when I would like to run Linux on my new build. Will I still be able to do so?
Yes, just depends on the distro you plan to use, "Linux" is very wide term, there's hundreds of distros out there. Linux in general includes wide variety of generic drivers but dedicated drivers are hard to come by and take certain knowledge to install even when they exist. Whatever distro you choose, make sure it's latest one. https://www.distrowatch.com/
Good part of Linux is that a live version run from USB or CD/DVD could be run to try it without actually installing to disk.
https://www.linuxliveusb.com/ can help you download many distros and make live USB.